Two different techniques extended far-field microscopy to nanoscopy - 2/3 of the Nobel prize was awarded to Eric Betzig and William Moerner for the development of single-molecule microscopy and 1/3 of the Prize was awarded to Stefan Hell for inventing stimulated emission depletion (STED) microscopy.

STED is a technique that reduces the size of a fluorescent region excited by diffraction-limited scanning laser spot by optical de-excitation of the fluorophores with doughnut-shaped depletion beam, and hence allowing imaging with nanoscale resolution without collecting multiple images of a sample. It should be mentioned, that the depletion of the excited state of a fluorophore is not restricted to the stimulated emission, but any process allowing spatially modulated excited state depletion could be utilized.

Superresolution fluorescence microscopy, or, more precisely, the STED counterpart of two-photon microscopy (2PM) , is one of the main research topics in Nano2Fun team. That imaging technique merges the advantages of STED and 2PM microscopy, significantly improving the resolution of 2PM. Another technique of interest of Nano2Fun project is STED-enhanced two-photon photopolymerization. Here the physical principle is the same: depletion beam is deactivating photoinitiators in an outer region of the excitation area, thus tightening the volume (voxel) where photopolymerization reaction takes place, so structures with features down to 80 nm could be created.

Although STED technique is well-established nowadays, and STED instruments are commercially available, the set of suitable dyes and photoinitiators is very restricted, compared with conventional microscopy. But since there is no resolution limit of STED, because it depends only on the applied depletion beam intensity and photophysical properties of the dye (high quantum yield, photostability, high STED cross-sections, etc.), the development of appropriate fluorescent probes and photoinitiators is of crucial importance in further developing superresolution microscopy and photopolymerization to their functional application in bioimaging and nanofabrication.

Nano2Fun network is very proud that superresolution microscopy technique has gained recognition at the highest level, boosting research and innovation in many areas. That Nobel Award is a perfect motivation for the further development of optical microscopy methods and application. All researches working on STED or SM are co-winners of this prize and Nano2Fun is very happy to be among them.

As a postscriptum some pieces of advice from Nobel Laureates to young people:

“My best advice to young students is to think out of the box”

“In the end one has to boil down everything to very essentialthings to understand it and to synthesize it.Only then we can make fundamental inventions”

From the interview with Stefan Hell, the inventor of STED microscopy, Nobel laureate in chemistry

“My advice to young people would be: 'don’t jump on the bandwagon that already exists but to build your own bandwagon. Try to find an opportunity in something that is overlooked,..,and then try to curve your own path."

From the interview with Eric Betzig, the inventor of single-molecule microscopy, Nobel laureate in chemistry